Meteorologically driven trends in sea level rise

Abstract

Determining the rate of global sea level rise (GSLR) during the past century is critical to understanding recent changes to the global climate system. However, this is complicated by non-tidal, short-term, local sea-level variability that is orders of magnitude greater than the trend. While the non-dimensional North Atlantic Oscillation (NAO) index can explain some of this variability in the Atlantic, significant results have been largely restricted to Europe. We show that dimensional indices of the position and intensity of the atmospheric centers of action (COAs) comprising the NAO are correlated with a major fraction of the variability and trend at 5 Atlantic Ocean tide gauges since 1900. COA fluctuations are shown to influence winds, pressure and sea-surface temperatures, thereby influencing sea level via a suite of coastal oceanographic processes. These findings reduce variability in regional sea level rise estimates and indicate a meteorological driver of sea-level trends. Copyright 2007 by the American Geophysical Union.